GLP-1对胆碱缺乏氨基酸饮食介导的非酒精性脂肪肝肝纤维化大鼠的治疗作用

Effects of Glucagon-Like Peptide-1 Analog on CDAA Diet-Induced Models of Nonalcoholic Fatty Liver Fibrosis in Rats

目的观察胰高血糖素样肽1类似物(利拉鲁肽)对非酒精性脂肪肝肝纤维化大鼠的治疗效果。方法雄性SD大鼠63只随机分为两组,其中对照组21只予含胆碱的氨基酸饮食喂养,另一组42只予缺乏胆碱的氨基酸饮食建立非酒精性脂肪肝肝纤维化大鼠模型,第10周末处死对照组大鼠1只,处死缺乏胆碱的氨基酸饲料组大鼠2只,Masson胶原染色肝组织确定造模成功后,缺乏胆碱的氨基酸饮食组随机分为两组:治疗组(20只)予利拉鲁肽注射液经腹腔注射,模型组(20只)予等体积的生理盐水经腹腔注射。分别以造模成功后的第2、4、6、8周为时间点,检测各组大鼠的体质量、肝指数、转氨酶、肝纤维化指标及肝组织Masson染色结果。结果三组大鼠体质量均呈进行性增长,治疗2周后,治疗组的体质量开始较模型组下降(F=3.407 9,P=0.006),而肝重量和肝指数下降不明显(F=2.103 1,P=0.059;F=0.425 5,P=0.679);给药4周后治疗组肝重量较模型组有明显下降(F=3.543 6,P=0.004),给药6周后治疗组肝指数较模型组明显下降(F=15.403 1,P=0);治疗2周开始治疗组谷草转氨酶比模型组有明显下降(F=2.815 7,P=0.017),治疗过程中治疗组谷丙转氨酶水平虽较模型组降低但不明显;治疗2周后治疗组血清透明质酸较模型组降低(F=3.454 5,P=0.014),治疗4周后治疗组Ⅲ型前胶原蛋白含量较模型组降低(F=11.797 4,P=0);随着缺乏胆碱的氨基酸饮食喂养时间的延长,Masson染色及光镜观察肝组织病理学显示大鼠肝脏脂肪变性及肝纤维化程度逐渐加重,治疗4周开始,纤维组织增生较模型组减轻(F=3.674 2,P=0.003),差异有统计学意义,肝脏细胞的变性较轻,随着治疗时间的延长,纤维化进一步改善。结论缺乏胆碱的氨基酸饮食可诱导大鼠肝脏出现脂肪肝变,甚至肝纤维化;随着治疗时间的延长,胰高血糖素样肽1类似物利拉鲁肽可以改善这一病理生理过程甚至逆转早期肝纤维化。

Objective To investigate the protective effects of glucagon-like peptide-1(GLP-1)on Nonalcoholicfatty liver fibrosis(NAFLF)rats.Methods Sixty-three male SD rats were randomly divided into2groups,one of them(n=21)were fed with choline-supplemented L-amino acid-defined diet(CSAA)for the whole experiment process.Another group(n=43)were fed with choline deficent aminoacid-defined diet(CDAA)as the modeling group,and at theend of the tenth week,one of the CSAA group and two of the modeling group were sacrificed to confirm the modelingsuccess,then the modeling group was divided randomly into2equal groups,both continued with CDAA diet,but one ofthe group were given with intraperitoneal injection of Liraglutide(GLP-1,administered in the later8weeks),usingsaline as a control.The rats were sacrificed at the2nd、4th、6th、8th week of the intervention process respectively to obtainblood samples and liver tissues for analyzing the levels of serum aminotransferase(ALT),aspartate transferase(AST)using an automatic biochemical analyzer and the levels of liver fibrosis indexes such as hyaluronic acid(HA)and typeⅢprocollagen(PCⅢ)in serum andα-SMA in the liver tissues by ELISA or radioimmunoassay.TLR4and NF-κB proteinlevels in the liver tissues were detected by Western blot.Results All rats get a weight gain during the period.Comparedwith CDAA group,CDAA+GLP-1group showed significantly decreased of body weight(F=3.4079,P=0.006)and serumlevels of AST(F=2.8157,P=0.017),while liver weight had no significant decrease until the end of the4th week(F=2.1031,P=0.059),so did the serum levels of PCIII(F=11.7974,P=0),and the serum HA level decreased significantly at the endof the2nd week(F=3.4545,P=0.014),liver index decreased significantly at the end of the6th week(F=0.4255,P=0.679).Though serum levels of ALT of the CDAA+GLP-1group decreased compared to the CDAA group,the differencewas not significant(P>0.05).Continous feeded with CDAA diet aggravated the liver steatosis and fibrosis,the pathologicalsituation began to improve sinificantly after4weeks??treatment with GLP-1analog(F=3.6742,P=0.003).ConclusionCDAA diet can induce NAFLF rat model,while Liraglutide,the GLP-1analog can reduce CDAA diet-induced hepaticfibrosis,improve liver function,suggesting its potential as a therapeutic agent for early liver fibrosis.